title: Local recurrence following breast-conserving treatment in women aged 40 years or younger: trends in risk and the impact on prognosis in a population-based cohort of 1143 patients.
abstract: OBJECTIVE
  To evaluate trends in the risk of local recurrences after breast-conserving treatment (BCT) and to examine the impact of local recurrence (LR) on distant relapse-free survival in a large, population-based cohort of women aged ≤40 years with early-stage breast cancer.
  
  
  METHODS
  All women (n=1143) aged ≤40 years with early-stage (pT1-2/cT1-2, N0-2, M0) breast cancer who underwent BCT in the south of the Netherlands between 1988 and 2010 were included. BCT consisted of local excision of the tumour followed by irradiation of the breast.
  
  
  RESULTS
  After a median follow-up of 8.5 (0.1-24.6)years, 176 patients had developed an isolated LR. The 5-year LR-rate for the subgroups treated in the periods 1988-1998, 1999-2005 and 2006-2010 were 9.8% (95% confidence interval (CI) 7.1-12.5), 5.9% (95% CI 3.2-8.6) and 3.3% (95% CI 0.6-6.0), respectively (p=0.006). In a multivariate analysis, adjuvant systemic treatment was associated with a reduced risk of LR of almost 60% (hazard ratio (HR) 0.42; 95%CI 0.28-0.60; p<0.0001). Patients who experienced an early isolated LR (≤5 years after BCT) had a worse distant relapse-free survival compared to patients without an early LR (HR 1.83; 95% CI 1.27-2.64; p=0.001). Late local recurrences did not negatively affect distant relapse-free survival (HR 1.24; 95% CI 0.74-2.08; p=0.407).
  
  
  CONCLUSIONS
  Local control after BCT improved significantly over time and appeared to be closely related to the increased use and effectiveness of systemic therapy. These recent results underline the safety of BCT for young women with early-stage breast cancer.
authors.affiliation: Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: van Laar
authors.forename: M J C
authors.initials: MJ
authors.lastname: van der Sangen
authors.forename: P M P
authors.initials: PM
authors.lastname: Poortmans
authors.forename: G A P
authors.initials: GA
authors.lastname: Nieuwenhuijzen
authors.forename: J A
authors.initials: JA
authors.lastname: Roukema
authors.forename: R M H
authors.initials: RM
authors.lastname: Roumen
authors.forename: V C G
authors.initials: VC
authors.lastname: Tjan-Heijnen
authors.forename: A C
authors.initials: AC
authors.lastname: Voogd
mesh_terms: D000328:Adult; D000367:Age Factors; D001943:Breast Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000628:therapy*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology*; D009426:Netherlands / Q000453:epidemiology; D011379:Prognosis; D012307:Risk Factors; D055815:Young Adult
keywords: Breast carcinoma; Breast-conservation; Local recurrence; Prognosis; Risk; Young age